// SPDX-License-Identifier: GPL-2.0-or-later /* * Written 1992,1993 by Werner Almesberger * 22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980 * and date_dos2unix for date==0 by Igor Zhbanov(bsg@uniyar.ac.ru) * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. */ #include <linux/time.h> #include <linux/fs.h> #include <linux/slab.h> #include <linux/buffer_head.h> #include "exfat_raw.h" #include "exfat_fs.h" /* * exfat_fs_error reports a file system problem that might indicate fa data * corruption/inconsistency. Depending on 'errors' mount option the * panic() is called, or error message is printed FAT and nothing is done, * or filesystem is remounted read-only (default behavior). * In case the file system is remounted read-only, it can be made writable * again by remounting it. */ void __exfat_fs_error(struct super_block *sb, int report, const char *fmt, ...) { struct exfat_mount_options *opts = &EXFAT_SB(sb)->options; va_list args; struct va_format vaf; if (report) { va_start(args, fmt); vaf.fmt = fmt; vaf.va = &args; exfat_err(sb, "error, %pV", &vaf); va_end(args); } if (opts->errors == EXFAT_ERRORS_PANIC) { panic("exFAT-fs (%s): fs panic from previous error\n", sb->s_id); } else if (opts->errors == EXFAT_ERRORS_RO && !sb_rdonly(sb)) { sb->s_flags |= SB_RDONLY; exfat_err(sb, "Filesystem has been set read-only"); } } /* * exfat_msg() - print preformated EXFAT specific messages. * All logs except what uses exfat_fs_error() should be written by exfat_msg() */ void exfat_msg(struct super_block *sb, const char *level, const char *fmt, ...) { struct va_format vaf; va_list args; va_start(args, fmt); vaf.fmt = fmt; vaf.va = &args; /* level means KERN_ pacility level */ printk("%sexFAT-fs (%s): %pV\n", level, sb->s_id, &vaf); va_end(args); } #define SECS_PER_MIN (60) #define TIMEZONE_SEC(x) ((x) * 15 * SECS_PER_MIN) static void exfat_adjust_tz(struct timespec64 *ts, u8 tz_off) { if (tz_off <= 0x3F) ts->tv_sec -= TIMEZONE_SEC(tz_off); else /* 0x40 <= (tz_off & 0x7F) <=0x7F */ ts->tv_sec += TIMEZONE_SEC(0x80 - tz_off); } /* Convert a EXFAT time/date pair to a UNIX date (seconds since 1 1 70). */ void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts, u8 tz, __le16 time, __le16 date, u8 time_cs) { u16 t = le16_to_cpu(time); u16 d = le16_to_cpu(date); ts->tv_sec = mktime64(1980 + (d >> 9), d >> 5 & 0x000F, d & 0x001F, t >> 11, (t >> 5) & 0x003F, (t & 0x001F) << 1); /* time_cs field represent 0 ~ 199cs(1990 ms) */ if (time_cs) { ts->tv_sec += time_cs / 100; ts->tv_nsec = (time_cs % 100) * 10 * NSEC_PER_MSEC; } else ts->tv_nsec = 0; if (tz & EXFAT_TZ_VALID) /* Adjust timezone to UTC0. */ exfat_adjust_tz(ts, tz & ~EXFAT_TZ_VALID); else /* Convert from local time to UTC using time_offset. */ ts->tv_sec -= sbi->options.time_offset * SECS_PER_MIN; } /* Convert linear UNIX date to a EXFAT time/date pair. */ void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts, u8 *tz, __le16 *time, __le16 *date, u8 *time_cs) { struct tm tm; u16 t, d; time64_to_tm(ts->tv_sec, 0, &tm); t = (tm.tm_hour << 11) | (tm.tm_min << 5) | (tm.tm_sec >> 1); d = ((tm.tm_year - 80) << 9) | ((tm.tm_mon + 1) << 5) | tm.tm_mday; *time = cpu_to_le16(t); *date = cpu_to_le16(d); /* time_cs field represent 0 ~ 199cs(1990 ms) */ if (time_cs) *time_cs = (tm.tm_sec & 1) * 100 + ts->tv_nsec / (10 * NSEC_PER_MSEC); /* * Record 00h value for OffsetFromUtc field and 1 value for OffsetValid * to indicate that local time and UTC are the same. */ *tz = EXFAT_TZ_VALID; } /* * The timestamp for access_time has double seconds granularity. * (There is no 10msIncrement field for access_time unlike create/modify_time) * atime also has only a 2-second resolution. */ void exfat_truncate_atime(struct timespec64 *ts) { ts->tv_sec = round_down(ts->tv_sec, 2); ts->tv_nsec = 0; } u16 exfat_calc_chksum16(void *data, int len, u16 chksum, int type) { int i; u8 *c = (u8 *)data; for (i = 0; i < len; i++, c++) { if (unlikely(type == CS_DIR_ENTRY && (i == 2 || i == 3))) continue; chksum = ((chksum << 15) | (chksum >> 1)) + *c; } return chksum; } u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type) { int i; u8 *c = (u8 *)data; for (i = 0; i < len; i++, c++) { if (unlikely(type == CS_BOOT_SECTOR && (i == 106 || i == 107 || i == 112))) continue; chksum = ((chksum << 31) | (chksum >> 1)) + *c; } return chksum; } void exfat_update_bh(struct buffer_head *bh, int sync) { set_buffer_uptodate(bh); mark_buffer_dirty(bh); if (sync) sync_dirty_buffer(bh); } int exfat_update_bhs(struct buffer_head **bhs, int nr_bhs, int sync) { int i, err = 0; for (i = 0; i < nr_bhs; i++) { set_buffer_uptodate(bhs[i]); mark_buffer_dirty(bhs[i]); if (sync) write_dirty_buffer(bhs[i], 0); } for (i = 0; i < nr_bhs && sync; i++) { wait_on_buffer(bhs[i]); if (!err && !buffer_uptodate(bhs[i])) err = -EIO; } return err; } void exfat_chain_set(struct exfat_chain *ec, unsigned int dir, unsigned int size, unsigned char flags) { ec->dir = dir; ec->size = size; ec->flags = flags; } void exfat_chain_dup(struct exfat_chain *dup, struct exfat_chain *ec) { return exfat_chain_set(dup, ec->dir, ec->size, ec->flags); }